Here are some pics of the transmission/gearbox/frankenstein after remaking the pivoting bar and rethinking the design a bit. The big aluminum one will carry the magnet(s). Its bearing, one from a r/w head from a hard drive, will turn about the same axis as the pivot bar pivots, so it never moves with gear changes and the belt maintains a constant tension. It has a groove matching the other pulley(borrowed indefinitely from a cd-rom drive) machined around it. I put a different, bigger, gear on the servo because leaving that idler gear then adding the pulley, and therefore length, I needed to get further out to keep my linkage at a kosher angle.
|You can see the end of the bolt at the bottom of the pivot bar is not all the way screwed down. Itll all work out when the big aluminum pulley is mounted.|
|Here's a side view for good measure. You can actually see in this pic that the linkage is not yet attached to the copper gear. I still had to work out the height, which is now to the top of the pulley, not the idler, like it was.|